Specific Aims: Motion Control Inc. proposes to develop two new rugged, electric terminal devices (IDs) for heavy-duty work activities, both based upon the same rugged drive and motor. These IDs will be: the Work Hand and the Work Hook. These new terminal devices will be lighter in weight, can be used in more extreme environments, and will offer more versatile gripping shapes than existing electric TDs. Motion Control is perfectly positioned to build upon the development of the Motion Control (MC) Hand, and the Electric Terminal Device, which both utilize our 2-speed drive and are capable of 25 Ib. of pinch force. They both may include the option of the highly functional Flexion Wrist. Background: Modern electric arm prostheses have significant advantages over body-powered devices: freedom from uncomfortable control cables (also allowing greater work envelope), very high pinch force (requiring little effort), and a more natural appearance. However, existing electric work TDs are not durable enough for many work environments because of suceptibility to water and dirt, and are not designed for truly rugged work. The effort: During Phase I, Motion Control has designed and built engineering models of the two TDs based upon the same enclosed, water-resistant drive. These two engineering models have been tested favorably during Phase I. During Phase II these TDs will be further developed and clinically tested with prosthesis wearers. Result: The result of Phase II development and testing will be both the heavy-duty Work Hand and the Work Hook that are ready for commercialization. This system will give upper-limb deficient individuals the benefits of a highly functional externally powered work hand that is suitable for a very wide variety of work, home, and recreational environments.